In-line seed treating unit for air seeders

ABSTRACT

An in-line seed treating unit is provided for an air seeding implement to coat seeds carried by a flow of air through a product distribution line before being planted into the ground. The in-line seed treating unit includes a cylindrical housing having input and outlet ends located at opposing axial ends of the cylindrical housing to provide a generally linear overall flow path for the seed entrained air flow through the product distribution line. A baffle formed as a spiral flighting with an open center portion is disposed within the cylindrical housing to induce the air flow and entrained seeds in a spiral flow path along the housing axis and, thereby pushing the entrained seeds outwardly toward the inner wall of the housing. The seed treatment material is injected through an injection port located a distance less than one flighting pitch of the baffle from the beginning of the flighting so that the seed treatment material is dispersed within the air flow to coat the entrained seeds. Preferably, the in-line seed treating unit is formed as a modular component that can be inserted into any selected product distribution line on the air seeding implement.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims domestic priority on U.S. Provisional PatentApplication Ser. No. 60/086,519, filed May 22, 1998.

BACKGROUND OF THE INVENTION

This invention relates generally to agricultural planting equipment,commonly referred to as air seeders, and, more particularly, to amechanism for coating an airborne stream of small granular items such asseed, with substances in liquid or powdered form.

Seed treatment devices are known in the agricultural industry, as isreflected in Applicant's co-pending U.S. patent application Ser. No.08/794,884, filed Feb. 5, 1997, and entitled "Application of Coatings toSeeds, Etc.". This seed treating mechanism is positioned generallyremotely of the tanks in which the seed to be treated is transportedover the field. The seed treating unit receives the flow of seed fromthe air transport system, treats the seed in a cyclonic chamber anddischarges the seed to the ground engaging units in the air flow to beplanted into the ground.

Treatment of the seeds remotely of the transport tanks enables theoperator to handle only untreated seed, such that no special precautionsare necessary. The seed is coated with the desired treatment onlyimmediately before being planted into the ground. One example of thetreatment of seeds involves the coating of the seeds with treatmentfluids such as inoculants or fungicides within a seed delivery streambetween a seed storage tank and a ground-engaging tool.

Another aspect of the instant invention provides a convenient andefficient method of coating particles within the parameters of an aircart.

As used with respect to the instant invention, the term "treatmentfluid" is intended to cover both liquid and flowable solid or powderedsubstances that are introduced to the untreated seed as a coatingthereto. Such coating material can be in the form of insecticides,herbicides, trace elements, inoculants and fungicides. The term seed isused in reference to the discrete seed particles that are to be or havebeen coated; however, the term is intended to cover other types ofparticles that may benefit from coating using the disclosed inventions.

Known seeding implements, such as described in the aforementionedco-pending U.S. patent application Ser. No. 08/794,884, carry seeds froma storage facility, such as a tank, to a ground-depositing tool by meansof a flow of air. The flow of air is typically generated by a fan orcompressor that is mounted on the seeding implement. Seeding implements,generally termed air carts or air seeders, are known in the industrythat consist of one or more tanks for holding seed and or fertilizer, anair source such as a fan, and a metering and manifold system fordelivering particles from the tank into one or more air streams.

Typical known seed coating processes for coating seeds have generallybeen carried out on an in-factory basis. That is to say, machinery isprovided in which, for example, seeds are mixed with a coating materialin a fluidized bed arrangement. Because the coating process is carriedout in-factory, it is a relatively easy matter to ensure good qualitycontrol, especially as regards the thickness of the coating, and asregards the evenness of the thickness, over the seed, and seed to seed.When the coating is factory-applied, inevitably a long time must elapsebetween the application of the coating and the insertion of the seedinto the ground.

Generally, the factory-applied seed coating cannot include moisture, asmoisture might cause the seeds to deteriorate or even to germinate, theformer never being desirable and the latter not being desirable beforebeing planted into the ground. Often, however, it would be advantageousif a moisture content could be included in the coating, especially ifthe moisture were applied immediately before being inserted into theground as the moisture could facilitate germination of the seed.

Another known method of coating seed is the mixing of batches of seedwith treatment fluid on the farm prior to placing the seed in the aircart tank. This system is inefficient and requires the operator/farmerto handle the coated seed in some manner. Seed coated in this mannermust be used within a limited time frame of when it is coated, and thuscoated-seed not planted within a given time frame becomes wasted. Thistranslates to losses due to the costs of wasted seed and wastedtreatment fluids. This method also requires cleanup of the air carttanks and loading equipment after treated seed is handled.

For the system described in the aforementioned co-pending U.S. patentapplication Ser. No. 08/794,884, the primary goal is to provide a systemfor applying a desired coating to the seeds on the air seederimmediately prior to insertion into the ground, whereby the seeds areinserted in the ground only a second or two after being coated. As aresult, only the required number of seeds are coated, moisture need notbe excluded, and all in all a greater freedom of choice of coatingsubstances becomes available. Furthermore, wet or sticky materials canbe added to the list of possible coating substances.

An important requirement is that the seed be coated evenly, not onlyover the surface of each seed particle, but also from seed to seed.Accordingly, an important goal would be the application of the coatingto the seeds without compromising evenness and controllability of thecoating, even though the coating operation is done actually on the airseeder, and takes place even as the operation of seeding is beingcarried out.

Improvements to the seed treating mechanism described in theaforementioned co-pending U.S. patent application Ser. No. 08/794,884are desired and are reflected in the instant patent application.

SUMMARY OF THE INVENTION

It is an object of the instant invention to provide a mixing chamberdesign to enhance the treatment of seeds on the air seeder before theseed is inserted into the ground.

It is another object of this invention to provide a modular design suchthat the seed treating mechanism will enable treatment of the seedwithin an air stream that accommodates several different seedingoptions.

It is still another object of this invention to provide a seed treatmentsystem that can be mounted as an integral part of an air cart,particularly within the air cart manifold.

Using the improved seed treatment system design described below to treatseed in the air manifold after it has been metered into the air streamfrom the cart tank has several advantages, including:

1. The tank and metering systems of the air cart remain clean becausetreatment fluids do not come into contact with the tank or meteringcomponents.

2. Seed is treated in the air stream on its way to the plantingimplement. Thus the time lag between when the seed is treated and whenit is in the furrow is a matter of seconds. The treatment is fresh,moisture levels are maintained, and wasting of treatment and seeds isreduced.

3. The seed treatment system can be offered as an option on an air cartrather than on a planting implement--thus it can be used with a varietyof planting implements rather than being limited to the one it ismounted on.

4. The treatment unit can be offered in a variety of positions withinthe air cart manifold to enable different uses of the cart tanks. Themixing unit design lends itself well to a modular system that can beinstalled by the farmer in different locations on the air cart dependingon the cart configuration. Due to reduced space requirements, theoptions for mixing unit locations are numerous. A modular system enablesthe farmer to change the cart after usage, permitting the same air cartto be used for a variety of planting situations.

5. The treatment chamber provides a gentle option for treating seedsthat has a low pressure drop across it. Seeds are coated efficientlywith minimal damage. Impact on the air cart fan system is minimized.

6. The treatment chamber does not contain any moving parts and thus theseed treatment system has low maintenance requirements.

7. The treatment system enables the treating of small volumes of seed,without incurring substantial waste.

The mixing module concept disclosed herein has potential to be veryimportant to the agricultural industry. An air cart can be designed toreadily accept placement of mixing unit modules in a variety of placeswithin the manifold. The modules can be relatively small and easy toinstall and replace. For best efficiency, different modules can beprovided for different seed types, such that the internals of the mixingunit are varied depending on the seed size and shape. Thus a typicalfarm operation might have a single air cart with a few different sets ofmixing modules to give the farmer a number of seeding and fertilizingalternatives.

The invention utilizes a new in-line mixer design. Typical in-linemixers known have internal baffles designed to repeatedly split andrecombine the flow to mix two or more elements within a stream. Themethods used for splitting the flow are too aggressive for the coatingof seeds and can lead to seed damage. The in-line mixer of the inventionis new in that it does not split and recombine the flow, but instead itencourages particles, usually seeds, to roll along the same path as thecoating material with which it is to be mixed. The purpose of theinventive mixer is more to coat the particles with the treatment fluid,rather than to simply mix two elements. The in-line mixer of theinvention induces the particles to travel along a spiral path on theinternal wall of the mixing chamber. The spiral trajectory increases themixing path length within a straight unit length of pipe or tube, thusmixing time is increased. The pressure of the carrying fluid is enoughto coat each particle with the treatment fluid.

The typically known in-line mixers are additionally undesirable formixing seed with treatment fluids due to the demands they place on theair pressure system. A typical in-line mixer that splits and recombinesflow has a higher pressure-drop across it than a typical air pressuresystem on an air cart can handle. If a pressure drop across a mixer istoo high there is not enough pressure in the stream to effectively carrythe particles from the mixer to the implement ground engaging tools. Thein-line mixer design of the invention provides efficient mixing withminimized pressure drops--thus the impact on the cart air system isgreatly reduced.

These and other objects, features and advantages can be accomplishedaccording to the instant invention by providing an in-line seed treatingunit for an air seeding implement to coat seeds carried by a flow of airthrough a product distribution line before being planted into theground. The in-line seed treating unit includes a cylindrical housinghaving input and outlet ends located at opposing axial ends of thecylindrical housing to provide a generally linear overall flow path forthe seed entrained air flow through the product distribution line. Abaffle formed as a spiral flighting with an open center portion isdisposed within the cylindrical housing to induce the air flow andentrained seeds in a spiral flow path along the housing axis and,thereby pushing the entrained seeds outwardly toward the inner wall ofthe housing. The seed treatment material is injected through aninjection port located a distance equal to at least one flighting pitchof the baffle so that the seed treatment material is dispersed withinthe air flow to coat the entrained seeds. Preferably, the in-line seedtreating unit is formed as a modular component that can be inserted intoany selected product distribution line on the air seeding implement.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of this invention will be apparent upon consideration ofthe following detailed disclosure of the invention, especially whentaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a typical known air cart upon whichthe seed treating system incorporating the principles of the instantinvention might be placed;

FIG. 2 is a schematic diagram of a portion of the air cart of FIG. 1incorporating the instant invention into a two-tank air cartconfiguration with the inventive mixing units in the lower lies of theintermediate manifold, particles from both tanks being directed to themixing units;

FIG. 3 is a schematic diagram similar to FIG. 2, but depicting atwo-tank air cart configuration in which only the first tank carriesseed to be coated, the second tank carrying fertilizer, the mixing unitsbeing placed in the primary manifold such that the seed particles fromthe first tank only are directed through the mixing units;

FIG. 4 is a schematic diagram similar to FIG. 2, but depicting atwo-tank air cart configuration in which the mixing units are located ineither or both of the intermediate manifold lines such that seedparticles from either or both tanks are directed through the mixingunits;

FIG. 5 is a schematic diagram similar to FIG. 2, but depicting athree-tank air cart configuration in which the mixing units are locatedin the lower lines of the intermediate manifold, seed particles from allthree tanks being directed to the mixing units;

FIG. 6 is a schematic diagram depicting a three-tank air cart systemsimilar to that of FIG. 5, but with mixing units located in the primarymanifold between the second and third tanks, such that seed particlesfrom the first and third tanks are directed through the mixing units,particulate material from the third tank being combined into the airflow stream after the seed particles have been treated in the mixingunit;

FIG. 7 is a schematic diagram of a three-tank air cart, similar to FIG.6, but with the mixing units located in the secondary manifold such thatparticulate material from the first tank bypass the mixing units, andseed particles from the second and third tanks are combined in the airflow and then directed through the mixing unit;

FIG. 8 is a diagrammatic cross-sectional view of the mixing unitincorporating the principles of the instant invention, one wall of thechamber tube being removed; and

FIG. 9 is a cross sectional view of the mixing unit taken along lines9--9 of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An air seeder of the type on which the instant invention can be utilizedis shown in FIG. 1. The general principles of an insitu seed coatingapparatus in found in co-pending U.S. patent application Ser. No.08/794,884, filed Feb. 5, 1997, and entitled "Application of Coatings toSeeds, Etc.", the descriptive portions of which are incorporated hereinby reference. The air seeder 10 is generally provided with a wheeledframe 11 on which are supported two to three tanks 12-14 in which seedparticles and/or fertilizer are stored for utilization as the air seeder10 is transported over the ground by a prime mover, such as a tractor(not shown). The air seeder 10 includes a fan 15 that creates an airflow through a conduit system 16 into which the particulate material,such as the seed and fertilizer, is metered and fed to be transported toground engaging tools that place the seed into the ground.

The air flow from the fan 15 is channeled through air flow tubes 17,also referred to as conduits or runs, to convey material from the tanks12-14 to the ground engaging tools. The number of primary runs in theair cart manifold depends on the width of the seeding implement. Atypical number of runs is eight, but the number can vary substantially.Each run goes to a separate section of the implement where it is dividedto multiple ground engaging tools 5. For purposes of clarity, theDrawings only depict one run.

FIG. 1 represents a typical air cart 10 on which the mixing unit 20 maybe utilized. The example shown has three tanks, designated 12, 13, 14,for holding particles such as seed and or fertilizer. Metering systems30 below the tanks 12-14 direct particles from the tanks 12-14 into themanifold 18 below the tanks. An air supply system, in this case a fan15, provides pressurized air to the manifold 18. The pressurized aircarries the particles through a distribution system 19 from the manifold18 to ground engaging tools 5.

The in-line seed treating mechanism 20 is best seen in detail in FIGS. 8and 9, which depict the internal design of the in-line mixing unitmodule 22. The in-line mixing chamber 22 is provided with a spiralbaffle 25 positioned along the interior wall 16a of a tube 16 thatinduces mixing with reduced pressure drops and reduced potential fordamage to the carried seed particles. The central portion 26 of thespiral baffle 25 is open, allowing the central path of the chamber 22 tobe clear. The spiral baffle 25 induces a rotational motion into the flowof the seed particles which pulls the air stream and the particles tothe wall area 23 of the mixing chamber 22. The seed particles tend toroll along the wall 23 of the chamber 22 following the baffle 25 in aspiral trajectory. The treatment fluid is injected into the chamber atan injection point 24 such that it flows in a relatively wide streamalong the wall 23 and follows the same path as the rolling particles,enabling the seed particles to roll in the stream of treatment fluidand, thereby, become coated by the treatment material.

For the air stream to be utilized for spreading the fluid flow, theinjection point 24 must be located after the air stream has been inducedto rotate by the baffle 25. The preferred embodiment shown has the fluidinjection point 24 located one full pitch length after the start of thebaffle 25, i.e. one full rotation of the spiral baffle 25. The injectionpoint 24 is located in the top of the module 22; however, the exactlocation of the injection point 24 will vary with mixing module type andthe treatment fluid to be injected, and could be located as close to thebeginning of the baffle 25 as 1/4 of a pitch length.

The treatment fluid is preferably injected in the form of a drip orspray at a point sufficiently below the interior wall of the chambersuch that it is caught by the rotating air stream and dispersed into afan-shaped pattern on the side wall of the tube.

The treatment fluid then travels in a relatively broad stream along thesame path as the seed particles within the mixing module 22. Theinjection point 24 in the preferred embodiment shown is located adistance 27 below the top interior surface. The selected distance 27 hasan impact on the width of the stream of fluid. If the injection point 24is too close to the interior wall 23 of the chamber 22, the stream willbe too narrow because the air does not interact sufficiently with thestream to force the treatment fluid to spread out. The injection point22 is fed by a line 28 that is connected to a fluid mixing tank and pumpsystem (not shown).

Due to the centrifugal pull of the seed particle motion, the portion ofthe air passing straight through the open center of the chamber 22 doesnot carry a significant number of particles. In testing, the particleshave been found to be treated with good uniformity, thus substantiallyall of the particles are carried along the wall 23 of the chamber 22.The rotary motion of the particles tends to pull the air stream towardsthe wall 23; thus most of the air travels along the baffle 25 with theparticles.

The pitch, width, and length of the spiral baffle 25 can be varied fordifferent seed types. The baffle embodiment shown is similar to one usedfor treating peas. The overall length of the baffle 25 can be varieddepending on the shape of the seed or particle being treated. Roundseeds tend to roll readily and require fewer baffle rotations toencourage them to follow a spiral path with the treatment fluid. Thebaffle 25 can, therefore, be cut shorter with the round seeds, perhapsto even a half of a rotation of the baffle 25, which reduces thepressure drop across the module 22. Oblong seeds tend to require morebaffle rotations to hold them in the spiral path sufficiently long tocoat them with treatment fluid; thus the baffle 25 for oblong seeds mustbe either longer or have a shorter pitch to provide more rotations perlength of the baffle 25 and, therefore, the seed treating module 22.Smaller seeds and particles can be induced into a rotary path withnarrower baffle widths, enabling the opening in the center 26 to belarger, which reduces the pressure drop across the mixing module 22.

Other modifications of the apparatus 20 are also envisioned within thescope of the instant invention to accommodate different sized or shapedseeds. Canola seed, for example, is very small. It is believed that thisin-line seed treating concept can be utilized with canola seed bykeeping the baffle thickness the same as for other seeds, but reducingthe inside diameter of the tube. This configuration would increase thevelocity of the air/seed flow within the in-line seed treating unit 20.

Thus, it is possible to create different modules 22 for different seedtypes that optimize the performance of each unit in terms of pressurerequirements. It is also possible to use the wider baffle size forlarger particles to treat small particles effectively. The only drawbackto the use of a single module type would be relevant to the pressuredrops--the pressure losses across the module 22 still beingsubstantially improved in comparison to other mixing alternatives.

FIGS. 2 through 7 represent some of the possible locations for thein-line mixing unit 20. The ability to place the mixing unit 20 betweenthe cart tanks 12-14, as illustrated in FIGS. 3 and 6, provides asignificant improvement due to the size of the mixing unit 20. FIGS. 2to 4 represent a typical two tank air cart 10 with the mixing unit 20placed in different positions. FIGS. 5 to 7 represent a typical threetank air cart 10 with the mixing units placed in different positionswithin the manifold 18. All of the Drawings show the adaptability of themixing unit 20 to fit within the confines of an existing manifold line18.

In FIG. 2 seed is metered through a metering mechanism 30 from bothtanks 10 and 11. Valve 32 is set such that the seed from tank 11 joinswith seed from tank 10 in the manifold bottom line 18a. All seed isdirected through the mixing unit 20 located in lower manifold line 18b,and thus seed is coated before traveling in stream 40, represented by anarrow, to the seed distribution system on the implement.

In FIG. 3 the mixing unit 20 is located in the manifold lower line 18bsuch that only seed from tank 12 is coated. Valve 32 is set such thatfertilizer from tank 13 mixes with the coated seed and travels throughmanifold line 18a. Stream 42, represented by an arrow, carries coatedseed and uncoated fertilizer to the seed distribution system 19 on theimplement. Thus seed and fertilizer are placed in the ground together ina single shoot seeding operation.

In FIG. 4 two mixing units 20 are shown in both the bottom manifold line18a and the top manifold line 18c. Valve 32 is set such that theparticles metered from tank 13 do not mix with the particles meteredfrom tank 12. Thus either seed or fertilizer can be placed in eithertank and different treatment fluids can be added to the particles ineach mixing unit. For example, stream 43 may contain fertilizer treatedwith a slow release chemical, and steam 44 may contain seed treated witha fungicide. The particles from each stream 43, 44 are placed into theground in either different furrows or different portions of the samefurrow such that they do not come into direct contact.

FIG. 5 shows valves 34, 36 and 38 set such that seed metered from tanks12, 13 and 14 are all directed through the bottom manifold line 18a. Amixing unit 20 is located in line 18a such that stream 46 carriestreated seed from all of the tanks 12-14 to the distribution system 19on the implement.

FIG. 6 shows valves 34, 36 and 38 set in the same manner as shown inFIG. 5. The mixing unit 20 is located in the lower manifold line 18bbetween the tanks 13 and 14 such that only the particles metered fromtanks 12 and 13 are coated. Thus, fertilizer, or other particles theoperator doesn't want coated, can be metered into the bottom manifoldline 18a after the mixing unit 20. Stream 47 typically carries acombination of coated seed from tanks 12 and 13 and uncoated fertilizerfrom tank 14 to the distribution system 19 on the implement.

FIG. 7 shows valves 34, 36 and 38 set such that particles from tanks 13and 14 combine in the middle manifold line 18d, and particles from tank12 are kept separate in the bottom manifold line 18b. The mixing unit 20is located in the middle manifold line 18d so that stream 48 carriescoated particles, typically seed, through a distribution system 19 tospecific furrows formed in the ground. Stream 49 carries particles fromtank 12, typically fertilizer, to alternate locations in the ground suchthat they do not come into direct contact with the stream 48 particles.

A significant advantage to being able to move the mixing unit module 22is that some particles do not benefit from addition of treatment fluidwhile others do. Typically it is not desirable to mix treatment fluidwith fertilizer particles, while it is desirable to mix treatment fluidwith seeds. Fertilizer is not mixed with most treatment fluids for avariety of reasons. Many treatment fluids are very expensive, and itwould not be cost effective to treat fertilizer particles unnecessarily.Several fertilizer types are hygroscopic and readily absorb water, andthus, their properties change when they are mixed with treatment fluidsuch that they become difficult to transport within an air system.Testing of the mixing unit 20 has shown that the treated particlesabsorb enough of the treatment fluid within the mixing module 22 suchthat fertilizer added downstream of the module 22 does not noticeablychange.

The design of the mixing module 22 is such that the liquid dilution ofthe treatment fluid can be reduced in comparison to the amount of liquidrequired for mixing using prior art treatment chambers.

With some ground opener and seed/fertilizer combinations it is desirableto place the seed and fertilizer together in the same furrow. In thissituation seed from one air cart tank and fertilizer from another aircart tank are combined into a single air stream per run--this process iscommonly termed single shoot seeding. Since it is not desirable to coatfertilizer particles with treatment fluid, the seed must be coated priorto mixing with the fertilizer in a single shoot configuration. FIGS. 3and 6 illustrate the mixing unit in this configuration.

In addition to the cases shown in FIGS. 2 through 7, the mixing unit 20can be placed in any air/particle delivery line prior to the seedingimplement ground tools. Thus the mixing unit 20 can be placed anywhereon either the air cart or on the implement. One embodiment is to placemixing units 20 within the primary delivery lines on an implement priorto splitting the flows in a distribution header. The mixing unit 20 canbe designed to accommodate different size air lines and differentproduct flows by varying the internal dimensions of the spiral baffle 25within.

While the above description of the invention is directed to thepreferred embodiment of coating seed particles, one skilled in the artwill readily realize that slow release coatings are being developed totreat fertilizers as well. Accordingly, the use of the terms, seed orseed particle, above would also be applicable to fertilizer particles,or other particulate materials that might be applied to the groundduring the planting operation.

One skilled in the art will also recognize that the modular concept ofin-line seed or particulate treating described above can be configuredin a serial orientation, such that more than one coating can be appliedto the seed or particulate. Furthermore, the above-described in-linetreating apparatus can be used to add a second or subsequent treatmentto previously treated seeds or particulates.

It will be understood that changes in the details, materials, steps andarrangements of parts which have been described and illustrated toexplain the nature of the invention will occur to and may be made bythose skilled in the art upon a reading of this disclosure within theprinciples and scope of the invention. The foregoing descriptionillustrates the preferred embodiment of the invention; however,concepts, as based upon the description, may be employed in otherembodiments without departing from the scope of the invention.

Having thus described the invention, what is claimed is:
 1. In an airseeding implement for planting agricultural products into the ground,said air seeding implement having a wheeled frame, a storage tanksupported on said frame to contain a supply of agricultural seeds to beplanted into the ground; a fan mounted on said frame and being operableto create a flow of air; air flow tubes corresponding to said storagetank and being operably associated with said fan to receive said flow ofair, said air flow tubes having a diameter; a metering mechanism todistribute the agricultural seeds into said air flow tubes to be carriedby the air flow therein for delivery to a remote location for insertioninto the ground; and a supply of seed treatment material, theimprovement comprising:a generally linear seed treating unit connectedwith at least one of said air flow tubes downstream from said meteringmechanism and connected to said supply of seed treatment material tocoat said agricultural seeds with said seed treatment material as saidagricultural seeds are conveyed generally linearly within said air flowtubes, said seed treating unit including:a generally cylindrical housinghaving a diameter substantially equal to the diameter of said air flowtubes and defining an in-line flow path along an axis of said housing,said at least one air flow tube being connected to opposing ends of saidhousing along said axis; a baffle within said housing to direct saidagricultural seeds within said air flow radially outwardly toward saidhousing in a spiral flow path along said axis; and an injection port onsaid housing connected radially relative to said axis to inject saidsupply of seed treatment material into said housing at an injectionpoint for mixing within said air flow and coating said agriculturalseeds.
 2. The air seeding implement of claim 1 wherein said baffle isformed as a spiral flighting defining at least one revolution withinsaid housing.
 3. The air seeding implement of claim 2 wherein saidinjection point is located downstream from a input connection of saidair flow tube to said housing at a distance less than one pitch lengthof said baffle.
 4. The air seeding implement of claim 3 wherein saidbaffle has an open center portion corresponding to said axis of saidhousing.
 5. The air seeding implement of claim 4 wherein said seedingtreating unit is a module component that can be inserted in any selectedair flow tube.
 6. The air seeding implement of claim 5 wherein said airseeding implement is provided with two storage tanks containing a supplyof agricultural seeds and another agricultural product for planting inthe ground, said seed treating unit being positioned in a manifold linethat combines the metered seed and product upstream of said seedtreating unit such that both said seeds and said other agriculturalproduct are mixed with said seed treatment material.
 7. The air seedingimplement of claim 5 wherein said air seeding implement is provided withtwo storage tanks containing a supply of agricultural seeds and anotheragricultural product for planting in the ground, said seed treating unitbeing positioned in an air flow tube corresponding to said storage tankcontaining said seeds to coat said seeds with seed treatment materialbefore being combined in a manifold line that combines the metered seedand product downstream of said seed treating unit such that only saidseeds, and not said other agricultural product, is coated with said seedtreatment material.
 8. An apparatus for treating seeds on a air seedingimplement having a storage tank containing a supply of seeds to beplanted into the ground; a fan operable to create a flow of air; an airflow tube operably associated with said fan to receive said flow of air;a metering mechanism to distribute the seeds into said air flow tube tobe carried by the air flow therein for delivery to a remote location forinsertion into the ground; and a supply of seed treatment material,comprising:a generally cylindrical housing having an axis with an inputend and an outlet end axially located on opposing ends of said housing,said input end being connected to said air flow tube downstream of saidmetering mechanism, said outlet end being connected to said air flowtube to continue conveying said seeds to said remote location; a baffleformed as a spiral fighting defining a length of at least one-half of arevolution within said housing to direct said air flow in a spiral pathalong said axis within said housing; and an injection port connectedwith said supply of seed treatment material to introduce said seedtreatment material into said housing to be mixed into said air flow forcoating said seeds, said injection port being located at a distance lessthan one-half of the length of said spiral flighting from said inputend.
 9. The apparatus of claim 8 wherein said apparatus is formed as amodule that can be selectively inserted into any air flow tube on saidair seeding implement.
 10. The apparatus of claim 9 wherein said bafflehas an open center portion corresponding to said axis of said housing.11. The apparatus of claim 10 said air seeding implement is providedwith two storage tanks containing a supply of said seeds and anotheragricultural product for planting in the ground, said apparatus beingpositioned in a manifold line that combines the metered seed and productupstream of said apparatus such that both said seeds and said otheragricultural product are mixed with said seed treatment material. 12.The apparatus of claim 10 wherein said air seeding implement is providedwith two storage tanks containing a supply of said seeds and anotheragricultural product for planting in the ground, said apparatus beingpositioned in an air flow tube corresponding to said storage tankcontaining said seeds to coat said seeds with seed treatment materialbefore being combined in a manifold line that combines the metered seedand product downstream of said seed treating unit such that only saidseeds, and not said other agricultural product, is coated with said seedtreatment material.
 13. An air seeding implement for plantingagricultural products into the ground, comprising:a wheeled frame; astorage tank supported on said frame to contain a supply of agriculturalseeds to be planted into the ground; a fan mounted on said frame andbeing operable to create a flow of air; an air flow tube correspondingto said storage tank and being operably associated with said fan toreceive said flow of air; a metering mechanism to distribute theagricultural seeds into said air flow tube to be carried by the air flowtherein for delivery to a remote location for insertion into the ground;a supply of seed treatment material supported on said frame; and anin-line seed treating unit connected to said air flow tube downstream ofsaid metering mechanism and including:a generally cylindrical housinghaving an axis with an input end and an outlet end axially located onopposing ends of said housing, said input end and said outlet end beingconnected to said air flow tube to provide a generally linear flow pathfor said air flow; a baffle formed as a spiral flighting defining atleast two revolutions within said housing to direct said air flow in aspiral path along said axis within said housing; and an injection portconnected with said supply of seed treatment material to introduce saidseed treatment material into said housing to be mixed into said air flowfor coating said seeds, said injection port being located at least onepitch length of said baffle from said input end.
 14. The air seedingimplement of claim 13 further comprising a second storage tankcontaining a second supply of agricultural seeds for planting in theground, said in-line seed treating unit being positioned in a manifoldline that combines the metered seed from both said storage tanksupstream of said in-line seed treating unit such that the agriculturalseeds from both said storage tanks are coated simultaneously.
 15. Theair seeding implement of claim 13 further comprising a second storagetanks containing a supply of another agricultural product for plantingin the ground, said in-line seed treating unit being positioned in anair flow tube corresponding to said storage tank containing said seedsto coat said seeds with seed treatment material before being combined ina manifold line that combines the coated seed and other agriculturalproduct downstream of said seed treating unit such that only said seeds,and not said other agricultural product, is coated with said seedtreatment material.
 16. The air seeding implement of claim 13 furthercomprising a second storage tank containing a second supply ofagricultural seeds for planting in the ground and a third storage tankcontaining a supply of another agricultural product to be planted in theground with said agricultural seeds, said in-line seed treating unitbeing positioned in a manifold line that combines the metered seed fromboth said storage tanks that contain said agricultural seeds upstream ofsaid in-line seed treating unit such that the agricultural seeds fromboth said storage tanks are coated simultaneously, said manifold linereceiving said other agricultural product downstream of said in-lineseed treating unit.